Housing for circuit breakers



y 1937- W. A. EONNELL ET AL;

HOUSING FOR CIRCUIT BREAKERS 3 Sheets-Sheet 1 Filed 001;. 21, 1955ATTORNEY Jul 20, 1937. w. A. BONNELL ET AL HOUSING FOR CIRCUIT BREAKERSFiled Oct. 21, 1935 s Sheets-Sheet 2 July 20, 1937.

W. A. BONNELL ET AL.

HOUSING FOR CIRCUIT BREAKERS Filed Oct. 21, 1935 3 Sheets-Sheet 5 Willi?IHLWIQIWLF IIHIIIIHIH INVENTORS 102mg. Q in/mil ATTORNEY Rate-med July20, 1937 UNITED STATES PATENT @FFICE HQUSING FOR GERCUIIT BREAKERSApplication @ctcber 721, 1935, Serial No. 45,342

16 Claims.

This invention relates to housings for circuit breakers; moreparticularly to the provision of explosion-proof and water-proof meansfor encasing such breakers.

As is well-known, when a circuit breaker is tripped due to an overload,or manually set to an oil position, an arc is created which, in thepresence of an inflammable gas can produce a serious explosion. This isespecially so in coal mines where electrical apparatus is used to agreat extent.

It is, therefore, an object of this invention to provide means foreffectively encasing a circuit breaker to prevent any arc, which may becreated during the tripping of the circuit breaker, from ignitinginflammable gases surrounding the housing for the circuit breaker.

In mines, it is common practise to have a central control stationthrough which power passes from an outside source. This station is underthe supervision of an operator who attends to the circuit breaker andother switches.

From the central station, power lines extend to various motors and otherelectrical apparatus used in the mines. When it is necessary to repairthe motor or other apparatus, obviously the current must be shut off,and this is done through the circuit breakers. However, since thecentral station in which the circuit breakers are located 30 frequentlyare at a considerable distance from the apparatus being repaired, it isnecessary to provide means to prevent accidental or inadvertent closingof the circuit during the repair of the apparatus. Obviously, forexample, should a 35 motor be in the process of repair and the circuitis suddenly closed, there is a possibility or" a large flash beingproduced across the motor which would ignite the surrounding inflammablegas and create a disastrous explosion. 40 A further object of thisinvention is to provide means for preventing the removal of the cover ofa circuit breaker housing except when the circuit breaker is in the oilposition, thereby obviating the possibility of a flash being createdwith the circuit breaker unencased and exposed to the surroundinginflammable gas. A. further object is the provision of means for lockingthe circuit breaker in an off position by means of a plurality of locksso that during the repair of apparatus the circuit breaker cannot bemoved to the on position except when all or" the locks have beenremoved.

According to this feature of the invention, the operator in control ofthe circuit breaker would attach a lock to the circuit'breaker to holdit in (Cl. zoo-5c) an off position, and the repair man of the electricalapparatus would also attach a separate lock to the circuit breaker. itwill be seen that by means of this arrangement the circuit breakercannot be moved to an on position until both the repair man and thestation attendant are present to remove their looks.

A further object is the provision of a housing having a control leverfor operating a circuit breaker, which lever is provided with a shed forpreventing water seeping into the circuit breaker, and to also serve asa stop to limit the movement of the handle in both directions ofmovement.

A further object is the provision of a novel interlocking means on acasing for two circuit breakers to prevent the throwing of both circuitbreakers to the on position at the same time.

These and other advantageous objects which will later appear, areaccomplished by the simple and practical construction and arrangement ofparts hereinafter described and exhibited in the accompanying drawings,forming part hereof, and in which:

Fig. l is a plan view of a housing for a circuit breaker embodying ourinvention,

Fig. 2 is a plan view of a circuit breaker housing with the coverremoved,

Fig. 3 is a plan view of the inside surface of the cover of the circuitbreaker housing,

Fig. is a sectional view taken on line 4- 1 of Fig. l,

Fig. 5 is a sectional view taken on line 5-5 of Fig. l,

Fig. 6 is a sectional view showing details of the operating handle usedon the circuit breaker housing,

Fig. 7 is a plan view of a circuit breaker housring cover for twocircuit breakers,

Fig. 8 is a plan view of the inside surface of the cover of the housingshown in Fig. 7, showing in detail the interlocking means between thetwo operating handles mounted on the cover,

Fig. 9 is a fragmentary perspective view showing details of an operatinghandle used in connection with our invention, and

Fig. 10 is a perspective view, on a reduced scale, of the housing for acircuit breaker 'embodying our invention, showing the electrical cableswhich connect with the circuit breaker.

Referring to the drawings, in Fig. 4 there is shown a circuit breaker li of a conventional type, mounted on the back wall i2 of a rectangular,box-like metal casing having a top wall l3, bottom wall M, and sidewalls 85.

. cover 20.

The circuit breaker is provided with the usual relatively shortoperating lever IS.

The free edges of the walls of the casing are provided with outwardlyand inwardly extending flanges l1 and II respectively, which form, witha wall of the casing, a T-shape.

In order to comply with the requirements of certain regulatory bureausin charge of the inspection of equipment, with regard to the preventionof fire and explosions, the flanges l1 and I1 together must be ofsuflicient width to prevent a flame created within the casing frompassing out to gases surrounding the casing.

By providing the T-shape arrangement of the wall and flanges as abovedescribed and shown in the drawings the width of the flange IT can bedecreased.

Projecting from the corners of the casing are four studs I8 whichcooperate with apertures IS, in the cover to enable the same to beproperly positioned on the casing. The cover is provided with anoutwardly projecting bushing 2|, see Fig. 6, through which passes a stubshaft 22 having attached to one end thereof a lever or arm 23, providedwith a slot 24 in which the lever l6 of the circuit breaker moves.

The lever 23 is provided with depressed end portions 25 and 26 whichengage the flange I! when the circuit breaker has been moved to the onposition, thereby preventing the removal of the cover from the casingwhen the circuit breaker is in the on position.

Attached to the other end of the stub shaft 22 by means of a pin 21 is acylindrical head 28 having an apron 29 which encircles the bushing 2|,said apron extending to the outer surface of the Integral with the head28 is an operating handle 30.

Referring to Fig. 6 it will be seen that in order for a flame to reachthe outside of the casing by way of the stub shaft 22 and head 28, itwill be necessary for the flame to travel up along the stub shaft, thenover the outer edge of the bushing 2| then down along the space betweenthe apron 29 and the bushing 2|, then out between the apron 29 and thecover 20. In other words, it will be necessary for the flame to travelseveral inches, which is a safe distance considerably in excess of thatrequired by regulatory bureaus, thereby rendering the casingflame-proof.

Projecting outwardly from the head 28 is an arcuate flange 3| havingthree apertures 32, 33 and 34 therein, said flange being arranged sothatwhen the handle 30 is moved to the off position, it will lie beneath asimilar arcuate flange 35 projecting from the outer surface of the cover20, so that apertures 36, and 31, in the flange 35 will registerrespectively with apertures 32, and 33 in the flange 3|.

One edge of the flange 35 engages the lever to limit the movementthereof when it is moved to the on position, and the other edge of theflange 35 engages a lug 38 projecting from the head 28 to limit themovement of the handle in the opposite direction. By means of thisarrangement excessive stresses on the circuit breaker handle l6 areprevented, and the possibility of breaking the circuit breaker handle iseliminated.

The slot 24 in the lever 23 has rounded ends 39 giving the slot adumbbell shape. This shape of the slot enables the free movement of theelongated flat'circuit breaker handle l6 therein. When the circuitbreaker has moved to the trip position, the circuit breaker handle I6 isparallel to the slot 24 and rests substantially in the straight portionthereof. When the circuit breaker handle is moved to either the on oroff position, the handle will lie at an angle to the slot with the edgesthereof positioned in the rounded portions 39 in the slot.

Referring to Fig. 4 it will be seen that the top and bottom walls l3 and[4 are thickened at 40 and the side walls are similarly thickened toenable the casing to be tapped for the passage of conduits fromdifferent directions without decreasing the strength of the casing.

In operation, the cover is placed upon the casing as shown in Fig. 1,the cover being guided in position by means of the studs l8 and holes19, after which the cover is securely bolted into position. The circuitbreaker handle i6 is now positioned in the slot 24 and movements of thelever 23 are obviously transmitted to the circuit breaker handle I6.When the handle 30, on the outside of the cover is moved to the onposition, the depressed portions 25 and 26 engage the underside of theflange l1 and prevent removal of the cover. The studs 18 positioned inthe holes [9 of the cover prevent removal of the cover by preventingsliding movement of the cover in either direction.

When the handle 30 is moved to the off position or reset position,obviously the cover can be readily removed as the lever 23 will besubstantially in a position as shown in Fig. 3.

When an attendant desires to lock the lever in the off position, heinserts a padlock in the apertures 36 and 32. Should the repair mandesire to further lock it in the off position. he will insert a padlockin the apertures 33 and 31, and should an inspector or other persondesire to further lock the device in the off position, a padlock can beinserted through the apertures 34. It will be seen that when the leveris so locked in the off position, it cannot be moved to the on positionuntil all of the padlocks are removed. In other words, accidental movingof the lever to the on position during the repair of apparatus, forexample, is prevented, and the lever cannot be placed in the on positionuntil all of the persons concerned with the repair work are present toremove their respective padlocks.

The flanges I1 and I1 and the corresponding surface on the inside of thecover 20 are preferably ground in order to provide an air tight joint.However, if desired, grooves may be divided in the flanges to receive agasket to also provide an air tight joint.

From the above description it will be seen that we have provided arelatively simple housing for a circuit breaker which is explosive-proofand water-proof, and fool-proof. That is, the housing is provided withmeans to prevent excessive forces being applied to circuit breakerlever, means to prevent removal of the cover when the circuit breaker isin the on position, and means to prevent the accidental throwing of thecir-, cuit breaker to an on position during the re pair of theelectrical apparatus receiving power through the circuit. d

The operating levers 30 are mounted on the front cover of the boxesthereby enabling close gauging of a plurality of circuit breakers whichis not possible with operating handles on the side walls of the boxes.In some instances it is necessary to use two circuit breakers. Such acase will arise where power is. received from two independent sources,and it is not desirable aoeaeee e;

that power be received from the two sources at the same time. In. Fig.7, we have shown a hous ing for two circuit breakers, which housing isprovided with the cover 50, and having mounted thereon a pair ofoperating handles and which are of the same construction as describedabove, in connection with the single circuit breaker.

In Fig. 8 is shown the underside of the cover 50 in which it will beseen that the handles 5i and 52 are provided with levers 53 and it whichengage the underside of the flange iii of the casing shown in dottedlines in Fig. 8 of the drawings, for preventing removal of the cover..Obviously, the cover can only be removed when both circuit breakers arein the on position. I'he levers 53 and 54 are provided with slots forengaging the circuit breaker levers as has heretofore been described.The lever 55 is attached to a shaft 55 having a notch 58 adapted toreceive the pointed arm 51 of an arcuate lever pivoted at Similarly thelever 53 is attached to a shaft having a notch receiving the arm dd ofthe lever pivoted at 58.

From the above description of Fig. 8 it will be seen that the two leverscannot be moved from an off position at the same time. For example, whenthe lever 54 is moved to the on position, the arm 5? is moved out of thenotch 56 and the arm engages the shaft 55 causing the arm 60 to bepressed tightly into the notch in. the shaft 58 thereby locking thelever 53 from movement. Similarly if the lever 53 is moved from the ofiposition to the on position the lever M will be locked in the offposition.

By means of this arrangement, obviously, it is impossible for bothcircuit breakers to be thrown into an on position and draw currentsimultaneously from two independent sources while the cover is in.position on the circuit breaker casing.

The foregoing disclosure is to be regarded as descriptive andillustrative only, and not as restrictive or limitative of theinvention, of which obviously an embodiment may be constructed includingmany modifications without departing from the general scope hereinindicated and denoted in the appended claims.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent, is:

I 1. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing having alever mounted thereon, said lever engaging the circuit breaker lever tomove the latter to an off or on position, and means on the casingengaging the lever on the cover to prevent removal of the cover from thecasing When the circuit breaker is moved to the on position.

2. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing, a leverm0unt= ed on the cover engaging the circuit breaker lever to move thelatter to various positions, and means on the casing engaging the leveron the cover to prevent removal of the cover when the circuit breakerlever has been moved to a position to close the circuit breaker.

3. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, said casing having inwardlyprojecting flanges from the side walls thereof, a cover for the casing,and a lever rotatably mounted on said cover engaging the circuit breakerlever to move the latter to various positions, said circuit breakerlever moving in a plane perpendicular to the plane of the rotatablelever, said lever on the cover engaging said flanges to prevent removalof the cover when the circuit breaker lever is moved to the on position.

i. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing having abushing projecting from the outer side thereof, a stub shaft journalledin said bushing and passing through said cover, a lever attached to theinner end of said stub shaft and engaging the circuit breaker lever tomove the latter to various positions, a head attached to said stub shaftand having an apron extending down along the sides of said bushing to apoint adjacent the outer surfaces of said cover, and a handle attachedto said head.

5. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing, a stubshaft journalled in the casing and passing therethrough, a leverattached to the inner end of the stub shaft and engaging the circuitbreaker lever to move the latter to various positions, a head attachedto the outer end of the stub shaft, an arcuate flange projecting fromsaid head and having a plurality of apertures therein, a handle attachedto said head, and an arcuate flange projecting from said cover andhaving a plurality of apertures therein, said flanges being so arrangedthat the apertures therein will register when the circuit breaker leverhas been moved to the off position.

6. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing, a stubshaft journallecl in the casing and passing therethrough, a leverattached to the inner end of the stub shaft and engaging the circuitbreaker lever to move the latter to various positions, a head attachedto the outer end of the stub shaft, an arcuate flange projecting fromsaid head and having a plurality of apertures therein, a handle attachedto said head, and an arcuate flange projecting from said cover andhaving a plurality of apertures therein, said flanges being so arrangedthat the apertures therein will register when the circuit breaker leverhas been moved to the Oh position, the arcuate flange projecting fromthe cover being proportioned to act as a stop to limit the movements ofthe handle in both directions thereby preventing the application ofexcessive stresses in the circuit breaker lever.

7. In combination with a circuit breaker having a lever, a box-likerectangular casing in which the circuit breaker is mounted, a cover forthe casing, a lever mounted on the cover and engaging the circuitbreaker lever to move the latter to various positions, a flangeprojecting inwardly from the walls of the casing, said lever engagingsaid flange to prevent removal of the cover when the circuit breakerlever has been moved to the on position, said cover having apertures atthe corners thereof, and studs projecting from the flange of said casingand passing through said apertures in the cover to prevent slidingmovements of the cover on the casing.

8. In combination with a circuit breaker having a substantially flatlever, a casing in which said circuit breaker is mounted, a cover forthe casing, a lever mounted on said cover and having a slot therein inwhich said circuit breaker lever is positioned, said slot having adumbbell shape to enable the circuit breaker lever to freely movetherein at all positions of the lever mounted on the cover.

9. In combination with a pair of circuit breakers having levers, acasing for the circuit breakers, a cover for the casing, levers mountedon said cover engaging said circuit breaker levers to move the latter tovarious positions, and interlocking means to prevent the moving of bothcircuit breaker levers to the on position simultaneously, said levers onthe cover moving in planes transverse to the planes in which saidcircuit breaker levers move.

10. In combination with a pair of circuit breaker levers, a casing inwhich said circuit breakers are mounted, a cover for the casing, stubshafts passing through said cover and having levers mounted thereon,each of said stub shafts having a notch therein, said levers engagingthe circuit breaker levers to move the latter to various positions, alever pivotally mounted between said stub shafts and having pointed armsadapted to rest simultaneously in the notches in said stub shafts onlywhen the circuit breaker levers have been moved to the off position, andpreventing simultaneous movement of both circuit breaker levers to theon position.

11. In combination wth a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing having astub shaft rotatably mounted thereon, an arm fixed to said stub shaftand engaging the circuit breaker lever, a handle fixed to the stubshaft," and means on the casing engaging said arm to prevent removal ofthe cover from the casing when the circuit breaker lever is in the onposition.

12. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing, an armrotatably mounted on the cover and having a slot in which said circuitbreaker lever is positioned so that it loosely engages said arm, meanson the cover to rotate the arm to move the circuit breaker lever to aposition to close the circuit breaker, and means on the casing engagingsaid arm to prevent removal of the cover when the circuit breaker isclosed.

13. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing, an armrotatably mounted on the cover and having an elongated slot in whichsaid circuit breaker is positioned so that it loosely engages said arm,said arm being rotatable in a plane transverse to the plane of movementof the circuit breaker lever, and means on the cover to rotate the armto a position to close the circuit breaker.

14. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, a cover for the casing, an armrotatably mounted on the cover and having an elongated slot in whichsaid circuit breaker is positioned so that it loosely engages said arm,said arm being rotatable in a plane transverse to the plane of movementof the circuit breaker lever, means on the cover to rotate the arm to aposition to close the circuit breaker, and means on the casing engagingsaid arm to prevent removal of the cover when the circuit breaker isclosed.

15. In combination with a circuit breaker having a lever, a casing inwhich the circuit breaker is mounted, said casing having inwardlyprojecting flanges from the side walls thereof, a cover for the casing,and a lever rotatably mounted on said cover engaging the circuit breakerlever to move the latter to various positions, said circuit breakerlever moving in a plane perpendicular to the plane of the rotatablelever, said lever on the cover engaging said flanges to prevent removalof the cover when the circuit breaker lever is moved to the on position,and means to prevent sliding movement of the cover on the casing.

16. In combination with a pair of circuit breakers having levers, acasing for the circuit breakers, a cover for the casing, levers mountedon said cover engaging said circuit breaker levers to move the latter tovarious positions, interlocking means to prevent the moving of bothcircuit breaker levers to the on position simultaneously, said levers onthe cover moving in planes transverse to the planes in which saidcircuit breaker levers move, and means on the casing engaging a lever onthe cover when its associated circuit breaker lever has been moved tothe on position to prevent removal of the cover from the casing.

WILLIAM A. BONNELL. RICHARD J. SCHNEPF.

